The present invention relates generally to wheel alignment systems and more particularly to a laser-based wheel alignment system having a laser supporting attachment for a vehicle wheel spindle or hub.
The axes about which the front wheels of an automobile or truck turn as it travels down the road must be carefully set to minimize tire wear and insure safe and stable handling characteristics. The orientation of these axes is determined by three angles: 1) the toe-in angle, which specifies the angle between the rim of the wheels and a line drawn parallel to the direction in which the car is pointed; 2) the camber angle, which specifies the angle between the rim of the wheels and the vertical; and 3) the caster angle, which specifies the angle between the vertical and the axis about which the individual wheels turn when changing direction. These angles are typically specified individually for each wheel and for each model and make of vehicle and must be periodically tested and reset as the vehicle and tires age to insure continued economic and safe vehicle performance.
The alignment of the steerable wheels of motor vehicles with respect to camber, toe-in and caster measuring devices of axle measurement equipment must assume a position accurately defined with respect to a vehicle part. Prior art installations include fastening plates for the mounting of the measuring devices. The alignment of the plane of the fastening plate takes place parallel to the plane of the outer surface of the respective brake drum of the wheel at a distance by means of abutment pins connected with the fastening plate. In order that the end faces of the abutment pins are able to abut at the flat-machined reference wheel surface hub without having to disassemble the vehicle wheel, the wheel disk is provided with correspondingly constructed bores, through which extend the abutment pins. Arms with hook-shaped ends are used in the fastening of the installation to the wheel and extend about apertures of the wheel disk and are connected with the fastening plate. In this manner, the measurement equipment mounted on the fastening plate is retained supported on the brake drum or the wheel hub. It is thereby disadvantageous and costly in that it is not possible in practice to control the abutment of the end faces of the contact pins on the reference surface with simple mechanical means since the abutment surface is not freely accessible. If the abutment of all abutment pins on the reference surface is not assured, then incorrect adjustments of camber, toe-in or caster may result therefrom when unevenness of the reference surface are not noticed or dirt particles or metal chips are disposed between abutment pins and abutment surface or if the installation rests tilted or canted in the bore holes.
The present invention attaches a laser module directly to the vehicle wheel spindle or hub to provide a more accurate positioning of the laser.
A vehicle laser alignment system laser supporting attachment for mounting a laser module to either the wheel spindle or hub of a vehicle has a plurality of attachments for attaching to different vehicles. A laser module supporting mandrel has a cradle for supporting the laser module on one end and a mandrel to wheel adapter connection on the other end thereof and has a slot formed in the side of the mandrel. A mandrel-to-wheel adapter is selected for a particular vehicle and is removably attached to the mandrel on the mandrel-to-wheel adapter connection for attaching the mandrel to a specific vehicle. An adapter holding plate has a threaded opening therein and is sized to fit into the mandrel slot for bolting the mandrel to a specific mandrel-to-wheel adapter on one end of the mandrel. The threaded bolt removably fastens the mandrel-to-wheel adapter to the mandrel by bolting through the mandrel-to-wheel adapter into the adapter holding plate. The mandrel-to-wheel adapter can be rapidly changed for threadedly attaching the mandrel to the end of a threaded spindle or for bolting the mandrel onto the wheel hub.